Selenoprotein P Influences Colitis-Induced Tumorigenesis by Mediating Stemness and Oxidative Damage.

Patients with inflammatory bowel disease are at increased risk for colon cancer due to augmented oxidative stress. These patients also have compromised antioxidant defenses as the result of nutritional deficiencies. The micronutrient selenium is essential for selenoprotein production and is transported from the liver to target tissues via selenoprotein P (SEPP1). Target tissues also produce SEPP1, which is thought to possess an endogenous antioxidant function. Here, we have shown that mice with Sepp1 haploinsufficiency or mutations that disrupt either the selenium transport or the enzymatic domain of SEPP1 exhibit increased colitis-associated carcinogenesis as the result of increased genomic instability and promotion of a protumorigenic microenvironment. Reduced SEPP1 function markedly increased M2-polarized macrophages, indicating a role for SEPP1 in macrophage polarization and immune function. Furthermore, compared with partial loss, complete loss of SEPP1 substantially reduced tumor burden, in part due to increased apoptosis. Using intestinal organoid cultures, we found that, compared with those from WT animals, Sepp1-null cultures display increased stem cell characteristics that are coupled with increased ROS production, DNA damage, proliferation, decreased cell survival, and modulation of WNT signaling in response to H2O2-mediated oxidative stress. Together, these data demonstrate that SEPP1 influences inflammatory tumorigenesis by affecting genomic stability, the inflammatory microenvironment, and epithelial stem cell functions

Roles of AP-2 in clathrin-mediated endocytosis.

The notion that AP-2 clathrin adaptor is an essential component of an endocytic clathrin coat appears to conflict with recent observations that substantial AP-2 depletion, using RNA interference with synthesis of AP-2 subunits, fails to block uptake of certain ligands known to internalize through a clathrin-based pathway

A20, a modulator of smooth muscle cell proliferation and apoptosis, prevents and induces regression of neointimal hyperplasia

A20 is a NF‐κB‐dependent gene that has dual anti‐inflammatory and antiapoptotic functions in endothelial cells (EC). The function of A20 in smooth muscle cells (SMC) is unknown. We demonstrate that A20 is induced in SMC in response to inflammatory stimuli and serves an anti‐inflammatory function via blockade of NF‐κB and NF‐κB‐dependent proteins ICAM‐1 and MCP‐1. A20 inhibits SMC proliferation via increased expression of cyclin‐dependent kinase inhibitors p21waf1 and p27kip1. Surprisingly, A20 sensitizes SMC to cytokine‐ and Fas‐mediated apoptosis through a novel NO‐dependent mechanism. In vivo, adenoviral delivery of A20 to medial rat carotid artery SMC after balloon angioplasty prevents neointimal hyperplasia by blocking SMC proliferation and accelerating re‐endothelialization, without causing apoptosis. However, expression of A20 in established neointimal lesions leads to their regression through increased apoptosis. This is the first demonstration that A20 exerts two levels of control of vascular remodeling and healing. A20 prevents neointimal hyperplasia through combined anti‐inflammatory and antiproliferative functions in medial SMC. If SMC evade this first barrier and neointima is formed, A20 has a therapeutic potential by uniquely sensitizing neointimal SMC to apoptosis. A20‐based therapies hold promise for the prevention and treatment of neointimal disease.—Patel, V. I., Daniel, S., Longo, C. R., Shrikhande, G. V., Scali, S. T., Czismadia, E., Groft, C. M., Shukri, T., Motley‐Dore, C., Ramsey, H. E., Fisher, M. D., Grey, S. T., Arvelo, M. B., Ferran, C. A20, a modulator of smooth muscle cell proliferation and apoptosis, prevents and induces regression of neointimal hyperplasia. FASEB J. 20, 1418–1430 (2006)Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154452/1/fsb2fj054981com.pd

How Communication and Control Processes Improve Quality

In order to achieve excellence, an organization should use two key instruments—quality and an effi cient and effective communication process amongst all employees—so it can attain quality management. This chapter aims to examine whether organizational communication and quality are interrelated, in order to answer the following question: Is it necessary to improve communication within an organization so that quality management can be effi ciently and effectively pursued? For this purpose, data were collected through the administration of a questionnaire to the staff of a Portuguese public organization. The fi ndings showed that, in this organization, communication among employees of various sectors is satisfactory and that there is mutual help between them in order to improve the organizational performance

Two NAD-linked redox shuttles maintain the peroxisomal redox balance in Saccharomyces cerevisiae

In Saccharomyces cerevisiae, peroxisomes are the sole site of fatty acid β-oxidation. During this process, NAD(+) is reduced to NADH. When cells are grown on oleate medium, peroxisomal NADH is reoxidised to NAD(+) by malate dehydrogenase (Mdh3p) and reduction equivalents are transferred to the cytosol by the malate/oxaloacetate shuttle. The ultimate step in lysine biosynthesis, the NAD(+)-dependent dehydrogenation of saccharopine to lysine, is another NAD(+)-dependent reaction performed inside peroxisomes. We have found that in glucose grown cells, both the malate/oxaloacetate shuttle and a glycerol-3-phosphate dehydrogenase 1(Gpd1p)-dependent shuttle are able to maintain the intraperoxisomal redox balance. Single mutants in MDH3 or GPD1 grow on lysine-deficient medium, but an mdh3/gpd1Δ double mutant accumulates saccharopine and displays lysine bradytrophy. Lysine biosynthesis is restored when saccharopine dehydrogenase is mislocalised to the cytosol in mdh3/gpd1Δ cells. We conclude that the availability of intraperoxisomal NAD(+) required for saccharopine dehydrogenase activity can be sustained by both shuttles. The extent to which each of these shuttles contributes to the intraperoxisomal redox balance may depend on the growth medium. We propose that the presence of multiple peroxisomal redox shuttles allows eukaryotic cells to maintain the peroxisomal redox status under different metabolic conditions

A Spontaneous Mutation in Contactin 1 in the Mouse

Mutations in the gene encoding the immunoglobulin-superfamily member cell adhesion molecule contactin1 (CNTN1) cause lethal congenital myopathy in human patients and neurodevelopmental phenotypes in knockout mice. Whether the mutant mice provide an accurate model of the human disease is unclear; resolving this will require additional functional tests of the neuromuscular system and examination of Cntn1 mutations on different genetic backgrounds that may influence the phenotype. Toward these ends, we have analyzed a new, spontaneous mutation in the mouse Cntn1 gene that arose in a BALB/c genetic background. The overt phenotype is very similar to the knockout of Cntn1, with affected animals having reduced body weight, a failure to thrive, locomotor abnormalities, and a lifespan of 2–3 weeks. Mice homozygous for the new allele have CNTN1 protein undetectable by western blotting, suggesting that it is a null or very severe hypomorph. In an analysis of neuromuscular function, neuromuscular junctions had normal morphology, consistent with previous studies in knockout mice, and the muscles were able to generate appropriate force when normalized for their reduced size in late stage animals. Therefore, the Cntn1 mutant mice do not show evidence for a myopathy, but instead the phenotype is likely to be caused by dysfunction in the nervous system. Given the similarity of CNTN1 to other Ig-superfamily proteins such as DSCAMs, we also characterized the expression and localization of Cntn1 in the retinas of mutant mice for developmental defects. Despite widespread expression, no anomalies in retinal anatomy were detected histologically or using a battery of cell-type specific antibodies. We therefore conclude that the phenotype of the Cntn1 mice arises from dysfunction in the brain, spinal cord or peripheral nervous system, and is similar in either a BALB/c or B6;129;Black Swiss background, raising a possible discordance between the mouse and human phenotypes resulting from Cntn1 mutations

The making of a mammalian peroxisome, version 2.0: mitochondria get into the mix

This is the author accepted manuscript. The final version is available from Nature Publishing Group via the DOI in this record.A recent report from the laboratory of Heidi McBride (McGill University) presents a role for mitochondria in the de novo biogenesis of peroxisomes in mammalian cells (1). Peroxisomes are essential organelles responsible for a wide variety of biochemical functions, from the generation of bile, to plasmalogen synthesis, reduction of peroxides, and the oxidation of very long chain fatty acids (2). Like mitochondria, peroxisomes proliferate primarily through growth and division of pre-existing peroxisomes (3-6). However, unlike mitochondria, peroxisomes do not fuse (5,7); further, and perhaps most importantly, they can also be born de novo, a process thought to occur through the generation of pre-peroxisomal vesicles that originate from the endoplasmic reticulum (reviewed in (8,9). De novo peroxisome biogenesis has been extensively studies in yeast, with a major focus on the role of the ER in this process. Comprehensive studies in mammalian cells are, however, scarce (5,10-12). By exploiting patient cells lacking mature peroxisomes, Sugiura et al. (1) now assign a role to ER and mitochondria in de novo mammalian peroxisome biogenesis by showing that the formation of immature preperoxisomes occurs through the fusion of Pex3- / Pex14-containing mitochondriaderived vesicles with Pex16-containing ER-derived vesicles

Determination of EGFR Endocytosis Kinetic by Auto-Regulatory Association of PLD1 with mu 2

Background: Upon ligand binding, cell surface signaling receptors are internalized through a process tightly regulated by endocytic proteins and adaptor protein 2 (AP2) to orchestrate them. Although the molecular identities and roles of endocytic proteins are becoming clearer, it is still unclear what determines the receptor endocytosis kinetics which is mainly regulated by the accumulation of endocytic apparatus to the activated receptors. Methodology/Principal Findings: Here we employed the kinetic analysis of endocytosis and adaptor recruitment to show that ??2, a subunit of AP2 interacts directly with phospholipase D (PLD)1, a receptor-associated signaling protein and this facilitates the membrane recruitment of AP2 and the endocytosis of epidermal growth factor receptor (EGFR). We also demonstrate that the PLD1-??2 interaction requires the binding of PLD1 with phosphatidic acid, its own product. Conclusions/Significance: These results suggest that the temporal regulation of EGFR endocytosis is achieved by auto-regulatory PLD1 which senses the receptor activation and triggers the translocation of AP2 near to the activated receptor.open3

Opportunistic Sampling of Roadkill as an Entry Point to Accessing Natural Products Assembled by Bacteria Associated with Non-anthropoidal Mammalian Microbiomes

Few secondary metabolites have been reported from mammalian microbiome bacteria despite the large numbers of diverse taxa that inhabit warm-blooded higher vertebrates. As a means to investigate natural products from these microorganisms, an opportunistic sampling protocol was developed, which focused on exploring bacteria isolated from roadkill mammals. This initiative was made possible through the establishment of a newly created discovery pipeline, which couples laser ablation electrospray ionization mass spectrometry (LAESIMS) with bioassay testing, to target biologically active metabolites from microbiome-associated bacteria. To illustrate this process, this report focuses on samples obtained from the ear of a roadkill opossum (Dideiphis virginiana) as the source of two bacterial isolates (Pseudomonas sp. and Serratia sp.) that produced several new and known cyclic lipodepsipeptides (viscosin and serrawettins, respectively). These natural products inhibited biofilm formation by the human pathogenic yeast Candida albicans at concentrations well below those required to inhibit yeast viability. Phylogenetic analysis of 16S rRNA gene sequence libraries revealed the presence of diverse microbial communities associated with different sites throughout the opossum carcass. A putative biosynthetic pathway responsible for the production of the new serrawettin analogues was identified by sequencing the genome of the Serratia sp. isolate. This study provides a functional roadmap to carrying out the systematic investigation of the genomic, microbiological, and chemical parameters related to the production of natural products made by bacteria associated with non-anthropoidal mammalian microbiomes. Discoveries emerging from these studies are anticipated to provide a working framework for efforts aimed at augmenting microbiomes to deliver beneficial natural products to a host.Research reported in this publication was supported by the National Institutes of Health, National Institute of Allergy and Infectious Diseases (1R21AI101487) (R.H.C. and B.S.S.). X-ray data were collected by L. Thomas in the OU Macromolecular Crystallography Laboratory, which is supported, in part, by an Institutional Development Award from the National Institutes of Health, General Medical Sciences (P20GM103640). The C. albicans SC5314 culture was kindly provided by A. Dongari-Bagtzoglou, University of Connecticut Health Center. The LC-ESIMS instrument used for this project was funded in part by a Challenge Grant from the Office of the Vice President for Research, University of Oklahoma, Norman Campus, and an award through the Shimadzu Equipment Grant Program (R.H.C.).Ye